ICA: PSD for individual ICs

Discussions
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1

Hello. How can I look at PSD for an individual ICA?

2

Hi @laraka & welcome to the Brainstorm community :blush:

In Brainstorm, it is currently possible to compute the PSD of signals before or after ICA, but not directly on the individual ICA components. ICA in Brainstorm is mainly designed for artifact removal rather than standalone component analysis. You can plot the time series of the ICs and their spatial topoplot. Check them here: https://neuroimage.usc.edu/brainstorm/Tutorials/Epilepsy#Artifact_cleaning_with_ICA

If your goal is to explore the spectral content of ICA components, you can write a script to export them to MATLAB and the analyse them; otherwise, EEGLAB provides built-in tools for this type of analysis:
https://eeglab.org/tutorials/06_RejectArtifacts/RunICA.html

You can also refer to this related discussion for more details:
https://neuroimage.usc.edu/forums/t/psd-for-components-from-ica/46784/2

3

Hello @laraka,

Currently, there is not an option to plot the IC PSDs on the fly (as the topographies).

However, it is possible to compute the IC PSDs by firstly obtaining the IC timeseries:

  1. Compute ICA for the raw data as usual, this will create a "Projector".

  2. Close the EEG raw file, and place it in Process1, then use the process Standardize > Apply montage, select the name of the ICA decomposition, and run the process

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  3. A new raw file will be created in the database with the IC time series, it is possible now to compute the PSD for these time series.

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PSD for components from ICA